(*  Author:     Florian Haftmann, TU Muenchen

Serializer for Scala.

*)

signature CODE_SCALA =

sig

  val setup: theory -> theory

end;

structure Code_Scala : CODE_SCALA =

struct

val target = "Scala";

open Basic_Code_Thingol;

open Code_Printer;

infixr 5 @@;

infixr 5 @|;

(** Scala serializer **)

fun print_scala_stmt labelled_name syntax_tyco syntax_const reserved args_num is_singleton deresolve =

  let

    val deresolve_base = Long_Name.base_name o deresolve;

    val lookup_tyvar = first_upper oo lookup_var;

    fun print_typ tyvars fxy (tycoexpr as tyco `%% tys) = (case syntax_tyco tyco

         of NONE => applify "[" "]" fxy

              ((str o deresolve) tyco) (map (print_typ tyvars NOBR) tys)

          | SOME (i, print) => print (print_typ tyvars) fxy tys)

      | print_typ tyvars fxy (ITyVar v) = (str o lookup_tyvar tyvars) v;

    fun print_typed tyvars p ty =

      Pretty.block [p, str ":", Pretty.brk 1, print_typ tyvars NOBR ty]

    fun print_var vars NONE = str "_"

      | print_var vars (SOME v) = (str o lookup_var vars) v

    fun print_term tyvars is_pat some_thm vars fxy (IConst c) =

          print_app tyvars is_pat some_thm vars fxy (c, [])

      | print_term tyvars is_pat some_thm vars fxy (t as (t1 `$ t2)) =

          (case Code_Thingol.unfold_const_app t

           of SOME app => print_app tyvars is_pat some_thm vars fxy app

            | _ => applify "(" ")" fxy

                (print_term tyvars is_pat some_thm vars BR t1)

                [print_term tyvars is_pat some_thm vars NOBR t2])

      | print_term tyvars is_pat some_thm vars fxy (IVar v) =

          print_var vars v

      | print_term tyvars is_pat some_thm vars fxy ((v, ty) `|=> t) =

          let

            val vars' = intro_vars (the_list v) vars;

          in

            concat [

              Pretty.block [str "(", print_typed tyvars (print_var vars' v) ty, str ")"],

              str "=>",

              print_term tyvars false some_thm vars' NOBR t

            ]

          end 

      | print_term tyvars is_pat some_thm vars fxy (ICase (cases as (_, t0))) =

          (case Code_Thingol.unfold_const_app t0

           of SOME (c_ts as ((c, _), _)) => if is_none (syntax_const c)

                then print_case tyvars some_thm vars fxy cases

                else print_app tyvars is_pat some_thm vars fxy c_ts

            | NONE => print_case tyvars some_thm vars fxy cases)

    and print_app tyvars is_pat some_thm vars fxy (app as ((c, ((tys, _), tys_args)), ts)) =

      let

        val k = length ts;

        val l = case syntax_const c of NONE => args_num c | SOME (l, _) => l;

        val tys' = if is_pat orelse

          (is_none (syntax_const c) andalso is_singleton c) then [] else tys;

        val (no_syntax, print') = case syntax_const c

         of NONE => (true, fn ts => applify "(" ")" fxy

              (applify "[" "]" NOBR ((str o deresolve) c) (map (print_typ tyvars NOBR) tys'))

                (map (print_term tyvars is_pat some_thm vars NOBR) ts))

          | SOME (_, print) => (false, fn ts =>

              print (print_term tyvars is_pat some_thm) some_thm vars fxy (ts ~~ take l tys_args));

      in if k = l then print' ts

      else if k < l then

        print_term tyvars is_pat some_thm vars fxy (Code_Thingol.eta_expand l app)

      else let

        val (ts1, ts23) = chop l ts;

      in

        Pretty.block (print' ts1 :: map (fn t => Pretty.block

          [str ".apply(", print_term tyvars is_pat some_thm vars NOBR t, str ")"]) ts23)

      end end

    and print_bind tyvars some_thm fxy p = gen_print_bind (print_term tyvars true) some_thm fxy p

    and print_case tyvars some_thm vars fxy (cases as ((_, [_]), _)) =

          let

            val (binds, body) = Code_Thingol.unfold_let (ICase cases);

            fun print_match ((pat, ty), t) vars =

              vars

              |> print_bind tyvars some_thm BR pat

              |>> (fn p => semicolon [Pretty.block [str "val", Pretty.brk 1, p,

                str ":", Pretty.brk 1, print_typ tyvars NOBR ty],

                  str "=", print_term tyvars false some_thm vars NOBR t])

            val (ps, vars') = fold_map print_match binds vars;

          in

            brackify_block fxy

              (str "{")

              (ps @| print_term tyvars false some_thm vars' NOBR body)

              (str "}")

          end

      | print_case tyvars some_thm vars fxy (((t, ty), clauses as _ :: _), _) =

          let

            fun print_select (pat, body) =

              let

                val (p, vars') = print_bind tyvars some_thm NOBR pat vars;

              in concat [str "case", p, str "=>", print_term tyvars false some_thm vars' NOBR body] end;

          in brackify_block fxy

            (concat [print_term tyvars false some_thm vars NOBR t, str "match", str "{"])

            (map print_select clauses)

            (str "}") 

          end

      | print_case tyvars some_thm vars fxy ((_, []), _) =

          (brackify fxy o Pretty.breaks o map str) ["error(\"empty case\")"];

    fun implicit_arguments tyvars vs vars =

      let

        val implicit_typ_ps = maps (fn (v, sort) => map (fn class => Pretty.block

          [(str o deresolve) class, str "[", (str o lookup_tyvar tyvars) v, str "]"]) sort) vs;

        val implicit_names = Name.variant_list [] (maps (fn (v, sort) => map (fn class =>

          lookup_tyvar tyvars v ^ "_" ^ (Long_Name.base_name o deresolve) class) sort) vs);

        val vars' = intro_vars implicit_names vars;

        val implicit_ps = map2 (fn v => fn p => concat [str (v ^ ":"), p])

          implicit_names implicit_typ_ps;

      in ((implicit_names, implicit_ps), vars') end;

    fun print_defhead tyvars vars p vs params tys implicits ty =

      Pretty.block [str "def ", print_typed tyvars (applify "(implicit " ")" NOBR

        (applify "(" ")" NOBR

          (applify "[" "]" NOBR p (map (str o lookup_tyvar tyvars o fst) vs))

            (map2 (fn param => fn ty => print_typed tyvars

                ((str o lookup_var vars) param) ty)

              params tys)) implicits) ty, str " ="]

    fun print_stmt (name, Code_Thingol.Fun (_, ((vs, ty), raw_eqs))) = (case filter (snd o snd) raw_eqs

         of [] =>

              let

                val (tys, ty') = Code_Thingol.unfold_fun ty;

                val params = Name.invents (snd reserved) "a" (length tys);

                val tyvars = intro_vars (map fst vs) reserved;

                val vars = intro_vars params reserved;

              in

                concat [print_defhead tyvars vars ((str o deresolve) name) vs params tys [] ty',

                  str ("error(\"" ^ name ^ "\")")]

              end

          | eqs =>

              let

                val tycos = fold (fn ((ts, t), _) =>

                  fold Code_Thingol.add_tyconames (t :: ts)) eqs [];

                val tyvars = reserved

                  |> intro_base_names

                       (is_none o syntax_tyco) deresolve tycos

                  |> intro_vars (map fst vs);

                val simple = case eqs

                 of [((ts, _), _)] => forall Code_Thingol.is_IVar ts

                  | _ => false;

                val consts = fold Code_Thingol.add_constnames

                  (map (snd o fst) eqs) [];

                val vars1 = reserved

                  |> intro_base_names

                       (is_none o syntax_const) deresolve consts

                val ((_, implicit_ps), vars2) = implicit_arguments tyvars vs vars1;

                val params = if simple then (map (fn IVar (SOME x) => x) o fst o fst o hd) eqs

                  else aux_params vars2 (map (fst o fst) eqs);

                val vars3 = intro_vars params vars2;

                val (tys, ty1) = Code_Thingol.unfold_fun ty;

                val (tys1, tys2) = chop (length params) tys;

                val ty2 = Library.foldr

                  (fn (ty1, ty2) => Code_Thingol.fun_tyco `%% [ty1, ty2]) (tys2, ty1);

                fun print_tuple [p] = p

                  | print_tuple ps = enum "," "(" ")" ps;

                fun print_rhs vars' ((_, t), (some_thm, _)) = print_term tyvars false some_thm vars' NOBR t;

                fun print_clause (eq as ((ts, _), (some_thm, _))) =

                  let

                    val vars' = intro_vars ((fold o Code_Thingol.fold_varnames) (insert (op =)) ts []) vars2;

                  in

                    concat [str "case", print_tuple (map (print_term tyvars true some_thm vars' NOBR) ts),

                      str "=>", print_rhs vars' eq]

                  end;

                val head = print_defhead tyvars vars3 ((str o deresolve) name) vs params tys1 implicit_ps ty2;

              in if simple then

                concat [head, print_rhs vars3 (hd eqs)]

              else

                Pretty.block_enclose

                  (concat [head, print_tuple (map (str o lookup_var vars3) params),

                    str "match", str "{"], str "}")

                  (map print_clause eqs)

              end)

      | print_stmt (name, Code_Thingol.Datatype (_, (vs, cos))) =

          let

            val tyvars = intro_vars (map fst vs) reserved;

            fun print_co (co, []) =

                  concat [str "final", str "case", str "object", (str o deresolve_base) co,

                    str "extends", applify "[" "]" NOBR ((str o deresolve_base) name)

                      (replicate (length vs) (str "Nothing"))]

              | print_co (co, tys) =

                  let

                    val fields = Name.names (snd reserved) "a" tys;

                    val vars = intro_vars (map fst fields) reserved;

                    fun add_typargs p = applify "[" "]" NOBR p

                      (map (str o lookup_tyvar tyvars o fst) vs);

                  in

                    concat [

                      applify "(" ")" NOBR

                        (add_typargs ((concat o map str) ["final", "case", "class", deresolve_base co]))

                        (map (uncurry (print_typed tyvars) o apfst str) fields),

                      str "extends",

                      add_typargs ((str o deresolve_base) name)

                    ]

                  end

          in

            Pretty.chunks (

              applify "[" "]" NOBR ((concat o map str) ["sealed", "class", deresolve_base name])

                (map (str o prefix "+" o lookup_tyvar tyvars o fst) vs)

              :: map print_co cos

            )

          end

      | print_stmt (name, Code_Thingol.Class (_, (v, (superclasses, classparams)))) =

          let

            val tyvars = intro_vars [v] reserved;

            val vs = [(v, [name])];

            fun add_typarg p = applify "[" "]" NOBR p [(str o lookup_tyvar tyvars) v];

            fun print_superclasses [] = NONE

              | print_superclasses classes = SOME (concat (str "extends"

                  :: separate (str "with") (map (add_typarg o str o deresolve o fst) classes)));

            fun print_tupled_typ ([], ty) =

                  print_typ tyvars NOBR ty

              | print_tupled_typ ([ty1], ty2) =

                  concat [print_typ tyvars BR ty1, str "=>", print_typ tyvars NOBR ty2]

              | print_tupled_typ (tys, ty) =

                  concat [enum "," "(" ")" (map (print_typ tyvars NOBR) tys),

                    str "=>", print_typ tyvars NOBR ty];

            fun print_classparam_val (classparam, ty) =

              concat [str "val", (str o suffix "$:" o deresolve_base) classparam,

                (print_tupled_typ o Code_Thingol.unfold_fun) ty]

            fun print_classparam_def (classparam, ty) =

              let

                val (tys, ty) = Code_Thingol.unfold_fun ty;

                val params = Name.invents (snd reserved) "a" (length tys);

                val vars = intro_vars params reserved;

                val (([implicit], [p_implicit]), vars') = implicit_arguments tyvars vs vars;

                val head = print_defhead tyvars vars' ((str o deresolve) classparam) vs params tys [p_implicit] ty;

              in

                concat [head, applify "(" ")" NOBR

                  (Pretty.block [str implicit, str ".", (str o suffix "$" o deresolve_base) classparam])

                  (map (str o lookup_var vars') params)]

              end;

          in

            Pretty.chunks (

              (Pretty.block_enclose

                (concat ([str "trait", add_typarg ((str o deresolve_base) name)]

                  @ the_list (print_superclasses superclasses) @ [str "{"]), str "}")

                (map print_classparam_val classparams))

              :: map print_classparam_def classparams

            )

          end

      | print_stmt (name, Code_Thingol.Classinst ((class, (tyco, vs)),

            (super_instances, classparam_insts))) =

          let

            val tyvars = intro_vars (map fst vs) reserved;

            val insttyp = tyco `%% map (ITyVar o fst) vs;

            val p_inst_typ = print_typ tyvars NOBR insttyp;

            fun add_typ_params p = applify "[" "]" NOBR p (map (str o lookup_tyvar tyvars o fst) vs);

            fun add_inst_typ p = Pretty.block [p, str "[", p_inst_typ, str "]"];

            val ((implicit_names, implicit_ps), vars) = implicit_arguments tyvars vs reserved;

            fun print_classparam_inst ((classparam, const as (_, (_, tys))), (thm, _)) =

              let

                val auxs = Name.invents (snd reserved) "a" (length tys);

                val vars = intro_vars auxs reserved;

                val args = if null auxs then [] else

                  [concat [enum "," "(" ")" (map2 (fn aux => fn ty => print_typed tyvars ((str o lookup_var vars) aux) ty)

                    auxs tys), str "=>"]];

              in 

                concat ([str "val", (str o suffix "$" o deresolve_base) classparam,

                  str "="] @ args @ [print_app tyvars false (SOME thm) vars NOBR (const, map (IVar o SOME) auxs)])

              end;

          in

            Pretty.chunks [

              Pretty.block_enclose

                (concat ([str "trait",

                    add_typ_params ((str o deresolve_base) name),

                    str "extends",

                    Pretty.block [(str o deresolve) class, str "[", p_inst_typ, str "]"]]

                    @ map (fn (_, (_, (superinst, _))) => add_typ_params (str ("with " ^ deresolve superinst)))

                      super_instances @| str "{"), str "}")

                (map (fn p => Pretty.block [str "implicit val arg$", p]) implicit_ps

                  @ map print_classparam_inst classparam_insts),

              concat [str "implicit", str (if null vs then "val" else "def"),

                applify "(implicit " ")" NOBR (applify "[" "]" NOBR

                  ((str o deresolve_base) name) (map (str o lookup_tyvar tyvars o fst) vs))

                    implicit_ps,

                  str "=", str "new", applify "[" "]" NOBR ((str o deresolve_base) name)

                      (map (str o lookup_tyvar tyvars o fst) vs),

                    Pretty.enum ";" "{ " " }" (map (str o (fn v => "val arg$" ^ v ^ " = " ^ v) o lookup_var vars)

                      implicit_names)]

            ]

          end;

  in print_stmt end;

fun scala_program_of_program labelled_name module_name reserved raw_module_alias program =

  let

    val the_module_name = the_default "Program" module_name;

    val module_alias = K (SOME the_module_name);

    val reserved = Name.make_context reserved;

    fun prepare_stmt (name, stmt) (nsps, stmts) =

      let

        val (_, base) = Code_Printer.dest_name name;

        val mk_name_stmt = yield_singleton Name.variants;

        fun add_class ((nsp_class, nsp_object), nsp_common) =

          let

            val (base', nsp_class') = mk_name_stmt base nsp_class

          in (base', ((nsp_class', nsp_object), Name.declare base' nsp_common)) end;

        fun add_object ((nsp_class, nsp_object), nsp_common) =

          let

            val (base', nsp_object') = mk_name_stmt base nsp_object

          in (base', ((nsp_class, nsp_object'), Name.declare base' nsp_common)) end;

        fun add_common upper ((nsp_class, nsp_object), nsp_common) =

          let

            val (base', nsp_common') =

              mk_name_stmt (if upper then first_upper base else base) nsp_common

          in (base', ((Name.declare base' nsp_class, Name.declare base' nsp_object), nsp_common')) end;

        val add_name = case stmt

         of Code_Thingol.Fun _ => add_object

          | Code_Thingol.Datatype _ => add_class

          | Code_Thingol.Datatypecons _ => add_common true

          | Code_Thingol.Class _ => add_class

          | Code_Thingol.Classrel _ => add_object

          | Code_Thingol.Classparam _ => add_object

          | Code_Thingol.Classinst _ => add_common false;

        fun add_stmt base' = case stmt

         of Code_Thingol.Datatypecons _ => cons (name, (base', NONE))

          | Code_Thingol.Classrel _ => cons (name, (base', NONE))

          | Code_Thingol.Classparam _ => cons (name, (base', NONE))

          | _ => cons (name, (base', SOME stmt));

      in

        nsps

        |> add_name

        |-> (fn base' => rpair (add_stmt base' stmts))

      end;

    val (_, sca_program) = fold prepare_stmt (AList.make (fn name => Graph.get_node program name)

      (Graph.strong_conn program |> flat)) (((reserved, reserved), reserved), []);

    fun deresolver name = (fst o the o AList.lookup (op =) sca_program) name

      handle Option => error ("Unknown statement name: " ^ labelled_name name);

  in (deresolver, (the_module_name, sca_program)) end;

fun serialize_scala raw_module_name labelled_name

    raw_reserved includes raw_module_alias

    _ syntax_tyco syntax_const (code_of_pretty, code_writeln) program stmt_names destination =

  let

    val presentation_stmt_names = Code_Target.stmt_names_of_destination destination;

    val module_name = if null presentation_stmt_names then raw_module_name else SOME "Code";

    val reserved = fold (insert (op =) o fst) includes raw_reserved;

    val (deresolver, (the_module_name, sca_program)) = scala_program_of_program labelled_name

      module_name reserved raw_module_alias program;

    val reserved = make_vars reserved;

    fun args_num c = case Graph.get_node program c

     of Code_Thingol.Fun (_, ((_, ty), [])) => (length o fst o Code_Thingol.unfold_fun) ty

      | Code_Thingol.Fun (_, (_, ((ts, _), _) :: _)) => length ts

      | Code_Thingol.Datatypecons (_, tyco) =>

          let val Code_Thingol.Datatype (_, (_, constrs)) = Graph.get_node program tyco

          in (length o the o AList.lookup (op =) constrs) c end

      | Code_Thingol.Classparam (_, class) =>

          let val Code_Thingol.Class (_, (_, (_, classparams))) = Graph.get_node program class

          in (length o fst o Code_Thingol.unfold_fun o the o AList.lookup (op =) classparams) c end;

    fun is_singleton c = case Graph.get_node program c

     of Code_Thingol.Datatypecons (_, tyco) =>

          let val Code_Thingol.Datatype (_, (_, constrs)) = Graph.get_node program tyco

          in (null o the o AList.lookup (op =) constrs) c end

      | _ => false;

    val print_stmt = print_scala_stmt labelled_name syntax_tyco syntax_const

      reserved args_num is_singleton deresolver;

    fun print_module name content =

      (name, Pretty.chunks [

        str ("object " ^ name ^ " {"),

        str "",

        content,

        str "",

        str "}"

      ]);

    fun serialize_module the_module_name sca_program =

      let

        val content = Pretty.chunks2 (map_filter

          (fn (name, (_, SOME stmt)) => SOME (print_stmt (name, stmt))

            | (_, (_, NONE)) => NONE) sca_program);

      in print_module the_module_name content end;

    fun check_destination destination =

      (File.check destination; destination);

    fun write_module destination (modlname, content) =

      let

        val filename = case modlname

         of "" => Path.explode "Main.scala"

          | _ => (Path.ext "scala" o Path.explode o implode o separate "/"

                o Long_Name.explode) modlname;

        val pathname = Path.append destination filename;

        val _ = File.mkdir (Path.dir pathname);

      in File.write pathname (code_of_pretty content) end

  in

    Code_Target.mk_serialization target NONE

      (fn NONE => K () o map (code_writeln o snd) | SOME file => K () o map

        (write_module (check_destination file)))

      (rpair [] o cat_lines o map (code_of_pretty o snd))

      (map (uncurry print_module) includes

        @| serialize_module the_module_name sca_program)

      destination

  end;

val literals = let

  fun char_scala c = if c = "'" then "\\'"

    else if c = "\"" then "\\\""

    else if c = "\\" then "\\\\"

    else let val k = ord c

    in if k < 32 orelse k > 126 then "\\" ^ radixstring (8, "0", k) else c end

  fun numeral_scala k = if k < 0

    then if k <= 2147483647 then "- " ^ string_of_int (~ k)

      else quote ("- " ^ string_of_int (~ k))

    else if k <= 2147483647 then string_of_int k

      else quote (string_of_int k)

in Literals {

  literal_char = Library.enclose "'" "'" o char_scala,

  literal_string = quote o translate_string char_scala,

  literal_numeral = fn k => "BigInt(" ^ numeral_scala k ^ ")",

  literal_positive_numeral = fn k => "Nat.Nat(" ^ numeral_scala k ^ ")",

  literal_naive_numeral = fn k => if k >= 0

    then string_of_int k else "(- " ^ string_of_int (~ k) ^ ")",

  literal_list = fn [] => str "Nil" | ps => Pretty.block [str "List", enum "," "(" ")" ps],

  infix_cons = (6, "::")

} end;

(** Isar setup **)

fun isar_seri_scala module_name =

  Code_Target.parse_args (Scan.succeed ())

  #> (fn () => serialize_scala module_name);

val setup =

  Code_Target.add_target (target, (isar_seri_scala, literals))

  #> Code_Target.add_syntax_tyco target "fun" (SOME (2, fn print_typ => fn fxy => fn [ty1, ty2] =>

      brackify_infix (1, R) fxy (

        print_typ BR ty1 (*product type vs. tupled arguments!*),

        str "=>",

        print_typ (INFX (1, R)) ty2

      )))

  #> fold (Code_Target.add_reserved target) [

      "abstract", "case", "catch", "class", "def", "do", "else", "extends", "false",

      "final", "finally", "for", "forSome", "if", "implicit", "import", "lazy",

      "match", "new", "null", "object", "override", "package", "private", "protected",

      "requires", "return", "sealed", "super", "this", "throw", "trait", "try",

      "true", "type", "val", "var", "while", "with", "yield"

    ]

  #> fold (Code_Target.add_reserved target) [

      "error", "apply", "List", "Nil", "BigInt"

    ];

end; (*struct*)